Cam operated electrical timer assembly with improved contact and associated peripheral rib cam

ABSTRACT

A timer switch utilizing a modular stacked configuration and a switching arrangement wherein one each of a pair of switch blades are responsive to a pair of cam surfaces separated by a peripheral rib of a single cam.

United States Patent [191 Brown Feb. 5, 1974 CAM OPERATED ELECTRICAL TIMER ASSEMBLY WITH IMPROVED CONTACT AND ASSOCIATED PERIPHERAL RIB CAM [75] Inventor: William Ray Brown, Beech Grove,

Ind.

[73] Assignee: P. R. Mallory & Co. Inc.,

Indianapolis, Ind.

[22] Filed: June 12, 1972 [21] Appl. No.: 262,137

[52] US. Cl. 200/38 B, 200/153 LB, 200/166 J [56 References Cited UNITED STATES PATENTS Straub 200/38 R Eggleston et al 200/56 R 3,553,720 1/1971 Brown 200/166 UX 3,478,181 1 1/1969 Buckerridge et a1 200/38 B 1,645,720 10/1927 Pfanstiehl 200/27 R X 3,652,814 3/1972 Kanazawa et a.l. 200/38 B X 3,679,988 7/ 1972 Haydon 200/38 B X Primary Examiner-James R. Scott Attorney, Agent, or FirmRichard l-l. Childress; Charles W. Hoffmann; Robert F. Meyer [57] ABSTRACT A timer switch utilizing a modular stacked configuration and a switching arrangement wherein one each of a pair of switch blades are responsive to a pair of cam surfaces separated by a peripheral rib of a single cam.

6 Claims, 5 Drawing Figures PATENIEDFEB sum 3.790.726

The present .invention is directed to minature electronic timers and more specifically to the type of electronic timers utilized in small appliances. One application for the present invention is'realized in providing an when blending specific types of liquids or foods or combinations thereof in a kitchen blender, the articles being blended will .not rise to the top of the blender when a constant speed is supplied to the impeller blade. When a pulsating current is provided to the motor of the blender, providing an on-off condition to the impellerof the blender, the liquid or food materials tend to be carried to the top level in the blender and then returned; back to the bottom thereby giving a thorough andcomplete blending operation. I i I The particular design of the present invention is such that it may be added to presently designed blenders and may consume a minimum amount of space within the housing of the blender. The present invention. may be placed into operation, into the circuitry of the blender, by selectively actuating an on-off switch on the blender to select either a pulse cycle or the standard cycle presently provided in the blender.

The. present invention is therfore concerned with providing ,a timer switch and has as one of its objects the provision of a timer switch constructed of modular discs, one of the discs providing a motor, a second disc providing a gear train and a third disc containing a program means and an electrical switch responsive to the program means for providing a quick-make and quickbreak of an electricalcontact.

, Another object of the present invention is to provide a timer switch that is relatively small in'size.

Still another object of the present invention is to provide a time switch that can be assembled together with relatively simple means.

A further object of the present invention is to provide a housing for the timer switch that will encompass a program means and provide rigid retaining means for a first and second switch blade that are responsive to the program means.

Another object of the present invention is to provide a modular switching disc for a timer switch that may be assembled with other modular switch discs to therefore increase the amount of program means available in a standard unit. Y

Still another object of the present invention is to provide a small compact switching arrangement that will provide a quick-make and quick-break of electrical contacts to aid in preventing arcing of the. contacts.

A further object of the present invention is to provide a timer switch having a cylindrical exterior.-

Yet another object of the present invention isto provide a pair of cooperatingxswitch blades that may be juxtaposition to each other and still ride the same program cam with a portion of the first switch blade extending throughthe plain of the second switch blade.

Still another object of the present invention is to provide a pair of electrical switches arranged so that one of the switch blades may be responsive to a program means and a second switch blade.

electronic pulse to a blender. It has been found that These and other objects will become more apparent from the following description and the accompanying drawings wherein:

FIG. I, is a perspective view of the timer switch.

FIG. 2, is an exploded perspective view of the switching and program means; I a

FIG. 3, is a vertical section throughthe switch disc and showing the program means. and the switching means in elevation:

FIG. 4, is a side view of the timer switch with a portion of the switch disc removed, and

FIG. 5,is a top view of the switch blades and the program means.

Generally speaking, the objects of the present invention are accomplished by providing a timer switch of modular construction including a modular disc-shaped motor, a modular disc-shaped gear train, and a modular disc-shaped switch assembly, which includes the program means, with the program means being driven by the modular gear train that is driven by the modular motor so that when the program means is rotated it will actuate a plurality of switch blades designed to ride on the periphery of the program means to move the switch blades with respect to each other and with one of the switch blades being responsive to a second switch blade. I

The timer switch, as illustrated, is assembled together by way'of coupling the disc-shaped motor to the discshaped gear train with key typelegs.( not shown) carried by "the motor engaging openings in the gear train and rotating the motor with respect to the gear train to lock the two together. The program ,means is then assembled on a shaft extending from the gear train and rotationaly coupled thereto. The disc-shaped switch housingis then positioned adjacent to the gear train and fastened thereto by a pair of C rings retained in posts extending from the gear train withxan insulative barrier separating the gear train from the switch housing. The disc-shaped switch housing covers and supports a pair of electrical switch blades. The electrical switch blades are provided near their'distal ends with an extended finger, which acts as cam followers, to ride on their respective cams. The fingers are designed to lie in a side by side relationship that will allow movement of the distal ends of the electrical switchblades without interfering with each other. As thefirst electrical switch blade follows its designated program it will be allowed to drop and therefore make contact through electrical contacts with the second electricalswitch blade, which is riding on its predetermined cam. As the program'means continues to rotate, the second electrical switch blade is allowed to drop to follow the contour of its cams.

As the second electrical switch blade is allowed to drop its electrical contact breaks electrical contact with the first electricalswitch blade contact to break the previous made electrical circuit. The cycle is repeated in the aforementioned sequence as long rent is supplied to the motor disc.

Located at the distal ends of the posts are threaded appertures to provide a mounting means for mounting the timer switch to an appliance.

Referring now to the drawings and more specifically to FIG. 1, the present inventions is incorporated in a timer switch 10 which includes a modular disc-shaped motor 12, a modular disc-shaped gear train 14 and a modular disc-shaped switch housing 16, which are an.

as curally aligned and rigidly coupled together to provide a stacked unit. The modular disc-shaped motor 12, provides a synchronous electromechanical drive to the gear train 14 and is rigidly coupled to the gear train 14, by way of a plurality of legs on the motor (not shown) which extend into the gear train housing and then rotated into a locking position. The gear train 14 includes a housing 14' which contains a plurality of gears (not shown) to provide the proper gear reduction from the motor 12. As seen in FIG. 2, the gear train 14 has an output shaft 19 which is rotated by the last gear in the gear train 14. Also located on the gear train 14, and staked thereto, is a pair of mounting posts 18. A discshaped insulating barrier 22, is placed at the rear of the gear train 14 and over the mounting posts 18 and output shaft 19.

As illustrated the dimension A of modular disc shaped motor 12 is greater than dimension B of the modular disc shaped gear train 14 and dimension of A, B, and C is less than the dimension D across the face of one of the modular discs. This combination provides a small, neat, and compact unit.

Modular disc-shaped switch housing 16 having a open end 16' is placed over the posts 18 and adjacent to the insulating barrier 22. Located in the modular disc-shaped switch housing is a program means 21, which includes a pair of electrical switch blades 24' and a rotatable program cam 23. The program cam 23 is rotatably coupled to the double-D output shaft 19 of the gear train 14 by the double-D aperture 28. The program cam 23 has a pair of independent cam surfaces, 30 and 32 that are separated by a peripheral rib 34.

Electrical switch blades 24, are carried in the switch housing with a first switch blade 36 rigidly carried in notch 36' in the housing 16 and a second switch blade 38 rigidly carried in notch 38. Switch blade 36 is provided near its first distal end with an external electrical terminal 40 and at the opposite distal end with a cam program follower 44. Located near the program follower 44 is an electrical contact 42. Second switch blade 38 is disposed immediately below the electrical switch blade 36 as viewed in FIGS. 2, 3, and 4. Electrical switch blade 38 is provided at one end with an external electrical terminal 46. The second end of the electrical switch blade 38 is provided with a program follower 50 and located near the program follower 50 is an electrical contact 48, which is positioned to mate with electrical contact 42 of switch blade 36. With first electrical switch blade 36 being disposed immediately above the second electrical switch blade 38, it is necessary to provide a means in both electrical switch blades that will allow movement of their respective cam program followers 44 and 50. To this end electrical switch blade 36 is provided, adjacent its cam program follower 44, with a window 44, which allows cam program follower 50 of electrical switch blade 38 to move therethrough. Electrical switch blade 38 is provided with a window 50 to allow movement of a cam program follower 44 therethrough. As viewed in FIG. 4, it can be seen that program follower 44 follows the contour of cam 30, with cam program follower 50 of electrical switch blade 38, following cam surface 32.

The modular disc shaped housing 16, with electrical switch blades 24 supported therein, is rigidly attached to the gear train with disc shaped insulated barrier 22 sandwiched there between. A pair of apertures 54 in the switch housing 16 allows the housing to fit over the mounting posts 18, which have been rigidly staked into the gear train 14. During the assembly of the housing 16 over the mounting posts 18, it is necessary to insert a tool (not shown) into aperture 60 to lift second switch blade 38, which in turn lifts switch blade 36 to clear cam 23. With the housing 16 in position as viewed in FIGS. 1 and 3, a pair of C rings 56 may be inserted into groves 58 in mounting posts 18 to retain housing 16 on posts 18.

It should be noted that if more than one electrical switching program is desired a plurality of switching programs may be obtained by increasing the length of the output shaft 19 and providing additional program cams 23 and additional modular disc shaped housings 16 with electrical switch blades 24 mounted in the additional housings. To retain a plurality of modular disc shaped housings on the modular disc shaped gear train 14 it is necessary to increase the length of the mounting posts 18 to retain the added switch housings l6.

OPERATION To actuate electrical switches 24 to provide an electrical switching circuit an electrical current may be applied to modular disc shaped motor 12 to drive the gear train 14. With the last gear of the gear train driving the output shaft 19, the program cam 23 will rotate in a predetermined direction, for example clockwise as viewed in FIG. 3. As program cam 23 rotates, the first electrical switch blade 36 with its program follower 44 is allowed to drop off of the cam surface 30 to allow the electrical contacts 42 and 48 to make or engage each other and thereby complete an electrical circuit through switch blades 36 and 38. As cam 23 continues to rotate in a clockwise direction the second electrical switch blade 38 with its program follower 50 is allowed to drop off of cam surface 32 to break the electrical circuit between electrical contacts 42 and 48. As the program cam 23 continues to rotate the cam followers 44 and 50 are lifted simultaneously thereby preventing physical contact of the electrical contacts 48 and 42 and preparing switch blades 24 to repeat the aforementioned program sequence.

The present invention provides a timer switch constructed of modular disc shape units that may be stacked together to provide a small, compact timer unit. A plurality of electrical programming sequences may be obtained by adding a plurality of modular disc shaped units 16 of identical construction and providing longer mounting posts 18. Combinations of timing sequence durations may be obtained by different configurations of the program cams 23 and/or by changing the modular disc shaped gear train 14 to provide a variation in the output speed of output shaft 19.

What is claimed is:

1. A timer comprising a motor, a gear train driven by said motor, and a switch operable through said gear train, said switch comprising:

a. a cam rotatably driven by said gear train, said cam having a pair of independent cam surfaces separated by a peripheral rib of said cam,

b. a pair of switch blades, one of which is disposed below the other to provide upper and lower switch blades,

0. cam followers disposed at a free end of each of said upper and lower switch blades, one each of said cam followers responsive to one of said independent cam surfaces, each of said cam followers hav- 4. A timer according to claim 3 wherein said discs are stacked together to provide an assembly, having a height which is less than that of a diameter of said discs.

5. A timer according to claim 2 wherein said switch disc is thinner than said motor disc.

6. A timer according to claim 2 wherein said switch disc is thinner than said gear train disc. 

2. A timer according to claim 1 wherein said motor is disc shaped and said gear train and switch are each substantially enclosed in a disc shaped housing to provide a motor disc, a gear train disc, and a switch disc.
 3. A timer switch according to claim 2 wherein said motor disc, said gear train disc and said switch disc are axialy stacked and fastened together.
 4. A timer according to claim 3 wherein said discs are stacked together to provide an assembly, having a height which is less than that of a diameter of said discs.
 5. A timer according to claim 2 wherein said switch disc is thinner than said motor disc.
 6. A timer according to claim 2 wherein said switch disc is thinner than said gear train disc. 